ABSTRACT
Sonic hedgehog(Shh) is a member of the hedgehog family in vertebrate. The Shh signaling pathway is mainly composed of a secreted glycoprotein, named Shh, two transmembrane proteins (Ptch and Smo) and the downstream transcription factor family Glis. It plays a vital role in the embryo development, especially in the neuronal system. Recent study have demonstrated that the Shh pathway is closely associated with the tumorigenesis of various tumors. Glioma, the most common malignant brain tumor of humans, is characterized by the rapid proliferation, infiltrative growth and high rate of relapse, and it is one of the brain tumors with poorest prognosis. Abnormal activation of multiple signaling pathways has been known to enhance the proliferation ability of glioma cells. Moreover, glioma is composed of various tumor cells and the glioma stem cells were endowed with the ability of self-renewal and unlimited proliferation, which plays a key role in the tumorigenesis, progress and relapse. Evidence has been found that Shh signaling pathway is closely assoicated with tumorigenesis of glioma. Herein we review the current knowledge on the components of Shh signaling pathway and its role in the tumorigenesis of glioma and glioma stem cells.